Monday, February 13, 2017

Oroville
Dam is an earthfill embankment dam on the Feather River east of the city of
Oroville, California, in the United States. At 770 feet (230 m) high, it is the
tallest dam in the U.S. and serves mainly for water supply, hydroelectricity
generation and flood control. Built by the California Department of Water
Resources (DWR), Oroville Dam is one of the key features of the California
State Water Project (SWP), one of two major projects passed that set up
California's statewide water system. Construction was initiated in 1961, and
despite numerous difficulties encountered during its construction, including
multiple floods and a major train wreck on the rail line used to transport
materials to the dam site, the embankment was topped out in 1967 and the entire
project was ready for use in 1968. Since its completion in 1968, the Oroville
Dam has allocated the flow of the Feather River from the Sacramento-San Joaquin
Delta into the State Water Project's California Aqueduct.. .. ..

Miles away
in China, the Yellow River or Huáng Hé,
is the third-longest river in Asia, following the Yangtze River and
Yenisei River, and the sixth-longest in the world at the estimated length of
5,464 km (3,395 mi). The river basin was
the birthplace of ancient Chinese civilization, and it was the most prosperous
region in early Chinese history. However, because of frequent devastating
floods and course changes produced by the continual elevation of the river bed
(due in part to manmade erosion upstream), sometimes above the level of its
surrounding farm fields, it also has the names China's Sorrow.

Back home in India, it is
all about water – which has flamed the States to become warring factions and
placed at Parliament and doorsteps of Apex Court. In a land fuelled by perceived notions, a
movie Dam 999 further fuelled the hysteria. Away from Cauvery river sharing snowballed another river issue, it originates from the Sivagiri peaks (1800m MSL)
of Sundaramala in Tamil Nadu; runs a
total length of about 244 Kms, flows northwards for 48 kms and at
Thekkady joins the west-flowing Mullayar – it is the river Periyar on which the
dam constructed is a bone of contention – the Mullaperiyar dam. It is a masonry gravity dam on the Periyar
River, located 881 m (2,890 ft) above mean sea level on the Cardamom Hills of
the Western Ghats in Thekkady, Idukki District of Kerala. It was constructed between 1887 and 1895 by
the British Government to divert water eastwards to Madras Presidency area (the
present-day Tamil Nadu). After a few
minor earthquakes in 1979 in regions surrounding the dam, security issues were
raised over its security. Since then, both the Kerala and TN governments have
been at loggerheads over the security issue.

Now on the subject
matter of the post – the Oroville dam – there have been mass evacuations, to prevent flooding as the reservoir behind
America’s tallest dam reached capacity and its main spillway was severely
damaged. On Saturday, water levels rose
so high that an emergency spillway was used for the first time. Officials
initially believed the measure worked. But on Sunday afternoon, as more water
from record storms flowed into Lake Oroville, officials detected a hole in the
emergency spillway. That prompted the evacuation order. Officials worry that a failure of the
emergency spillway could cause huge amounts of water to flow into the Feather
River, which runs through downtown Oroville, and other waterways. The result
could be flooding and levee failures for miles south of the dam, depending on how
much water is released.

Nearly 200,000
people remained under evacuation orders on Monday (13.2.2017) as California
authorities desperately battle to stop a collapse at the nation's tallest dam
that could unleash a 100 foot tsunami if it fails. Concerned officials warned
that in the worst case scenario a complete structural breakdown at the
emergency spillway of Oroville Dam would unleash a torrent of water that would
engulf Oroville within an hour. The ensuing flood from the 770-foot dam would
put the city of Oroville and several other low-lying communities along the
Feather River under 100ft of water. And amid the frantic evacuations, it
emerged overnight that federal and state officials and some of California's
largest water agencies rejected concerns 12 years ago about the precarious
state the dam - which was built between 1962 and 1968.

An aerial of the Oroville
Dam reveals the dangerous flooding at the spillway that has left the area in
imminent danger of a catastrophic flood !
A massive hole is causing major erosion around the Oroville Dam in
California – the hole formed Tuesday and
has continued to grow since then. If Oroville Dam were to suffer a massive
breach, water would get to the town of Oroville within an hour, according to
GIS maps maintained by CalFire. Within two hours, the small town of Briggs
would be affected. In three hours, Gridley would be hit. Water would reach Live
Oak in five hours.. it would take eight
to 12 hours for the water to get to Marysville and Yuba City. If the dam
completely failed, flood depths could reach more than 100 feet in Oroville and
up to 10 feet in Yuba City.

The dangerous
situation sparked the California National Guard to put out a notification to
all 23,000 soldiers and airmen to be ready to deploy if needed. The last time
an alert for the entire California National Guard was issued was the 1992
riots. And early on Monday morning,
relieved officials said that water had stopped pouring over the dam's emergency
spillway after they essentially rose 50-feet over a few days. They announced
that although not nearly out of the woods, the situation had improved. However,
another storm is predicted to hit the area by Friday, putting more strain on
the dam and potentially sparking a catastrophic failure.

There naturally was
panic as residents queued up evacuation. What they couldn't fit in their trunk
they piled as high as they could in their downstairs Yuba City apartment and
joined the line of traffic attempting to leave the city where they had moved
just three weeks ago. Panicked and angry residents sat in bumper-to-bumper
traffic hours after the evacuation order was given. A Red Cross spokeswoman
said more than 500 people were at an evacuation center in Chino, California.
The shelter had run out of blankets and cots, and a semi-tractor trailer with
1,000 more cots was stuck in the gridlock of traffic fleeing the potential
flooding, said Red Cross shelter manager Pam Deditch.

Acting Director
Department of Water Resources Bill Croyle said officials will be able to assess
the damage to the emergency spillway now that the lake levels have been
lowered. Croyle said the department will
continue releasing as much as 100,000 cubic feet per second from the main
spillway to try and reduce the dam's level by 50 feet ahead of storms forecast
to reach the area Wednesday. After years of drought Northern California has
endured several months of exceptionally wet weather. Oroville and other lakes
are brimming and have begun releasing water to make room for more runoff.